An international research team has mapped gene-expression changes in ageing mouse skeletal muscle, providing new insights into how the extracellular matrix (ECM) may contribute to muscle ageing and sarcopenia. Published in BMC Genomics, the study shows that ageing involves not only changes within muscle cells but also significant alterations in the molecular environment surrounding them.

Researchers examined gene-expression patterns in male mouse skeletal muscle at 2, 11 and 25 months of age, representing young adult, mature adult and aged stages. Rather than simply comparing young and old animals, the study aimed to distinguish changes associated with normal maturation from those specifically linked to ageing. The researchers found that many differences observed between 2- and 25-month-old mice had already emerged during maturation, suggesting that mature adult mice may provide a more suitable reference for studying age-related molecular changes.

The study focused on the muscle matrisome—the collection of genes associated with the extracellular matrix—and identified a transcriptomic “matreotype” of muscle ageing consisting of 58 genes. Notably, 95% of these genes were downregulated with age, indicating substantial changes in the molecular environment that supports muscle structure and function.

The researchers identified several ageing-associated processes, including structural remodelling, altered synaptic transmission, changes in extracellular matrix and angiogenesis-related pathways, and increased apoptosis-related activity. These findings suggest that changes in the ECM may influence cellular communication, blood-vessel function, tissue repair and muscle maintenance, potentially contributing to sarcopenia.

Overall, the research provides a broader view of muscle ageing, showing that age-related decline is accompanied by changes in the tissue environment surrounding muscle cells. Combining transcriptomic and proteomic approaches in future studies could help clarify how ECM remodelling contributes to muscle deterioration and identify potential targets for preserving muscle health during ageing.

Source: https://www.asiaresearchnews.com/content/ageing-muscle-leaves-molecular-fingerprint-its-supporting-matrix